1. Field of the Invention
The present invention relates to object tracking systems, and more particularly, to a multi-sensor system and method of fusing data from a plurality of sensors, for more accurately estimating the location of a given object.
2. Discussion of Prior Art
Object tracking and target profiling systems have been developed as part of safety applications in various industries, including the aviation and automotive industries. These systems utilize periodic or continuous detection of objects and control algorithms to estimate various planar parameters of an object, such as the relative object range, range rate (i.e., closing or opening velocity), and azimuth position (i.e., bearing), as well as three-dimensional parameters where applicable, such as altitude or elevation, so as to avoid, follow, or otherwise survey the object. It is apparent that the ability of these systems to provide accurate estimations is crucial to achieving the desired benefits of their applications.
Inaccurate assessments or missed detections, for example, can lead to false positives, collisions, and other system failures. In addition to physical malfunctions, however, it is appreciated by those ordinarily skilled in the art that the standard deviation of measurement for a particular sensor, plus background interference (typically modeled as white Gaussian noise) also provide a degree of inaccuracy inherent to all sensory performance systems. The imprecision of these systems in determining the exact location of the object present further concerns where utilized with intricate or crucial applications.
To improve the likelihood of object detection, a plurality of sensors is often utilized within a system. With respect to automotive applications, such as collision detection or lateral support systems, for example, these sensors may include GPS, FM-CW radars, pulse and FSK radars, and CCD's, CMOS, or other camera/video image processors. Irrespective of application, however, these multiple-observer configurations generally operate to detect the same object, so as to provide back-up or redundant means of detection, and therefore, do not typically improve the overall accuracy of the system above that of the most accurate sensor. Multi-observer systems that have been developed to increase accuracy, such as phased-array-multi-beam-radar systems, typically require complex construction and expensive equipment to operate.
Finally, where multiple-observer configurations are utilized, multiple sets of data are generated for each detected object and statically stored as tracks. Due to the multiplication of data, the tracks may become voluminous over time, thereby requiring expensive and cumbersome data storage and manipulation. The inability of these systems to remove inactive and otherwise useless tracks from the system, further results in wasted resources and possible confusion by the system, application, or user.